Integrated circuit device and method for manufacturing integrated circuit device

ABSTRACT

An object of the present invention is to provide a structure of a thin film circuit portion and a method for manufacturing a thin film circuit portion by which an electrode for connecting to an external portion can be easily formed under a thin film circuit. A stacked body including a first insulating film, a thin film circuit formed over one surface of the first insulating film, a second insulating film formed over the thin film circuit, an electrode formed over the second insulating film, and a resin film formed over the electrode, is formed. A conductive film is formed adjacent to the other surface of the first insulating film of the stacked body to be overlapped with the electrode. The conductive film is irradiated with a laser.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for manufacturing anintegrated circuit device, and further, relates to an integrated circuitdevice, a product using an integrated circuit device, and asemiconductor device.

2. Description of the Related Art

In recent years, development of a technique for displacing a thin filmcircuit provided over an insulating substrate has been carried out. Assuch a technique, for example, there has been a technique by which aseparation layer is provided between a thin film circuit and asubstrate, the separation layer is removed by using a gas containinghalogen to separate the thin film circuit from the supporting substrate,and then the thin film circuit is displaced over an object (see patentdocument 1).

-   [Patent document 1]: Japanese Patent Application Laid-Open No. Hei    8-254686

In the above mentioned technique disclosed in the patent document 1, asemiconductor integrated circuit having a structure in which a thin filmtransistor is sandwiched between a base film and an interlayerinsulating film and a passivation film such as a silicon nitride film,and an electrode being electrically connected to the thin filmtransistor is formed over the passivation film, is separated from asubstrate, and then the separated semiconductor integrated circuit isused as a driver circuit of a display device. That is, since thesemiconductor integrated circuit is separated from the substrate whilekeeping a state where the electrode for connecting to an externalportion is formed over the thin film transistor in advance, theelectrode for connecting to an external portion is not formed under thethin film transistor.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a structure of anintegrated circuit device and a method for manufacturing an integratedcircuit device by which an electrode for connecting to an externalportion can be easily formed under a thin film circuit.

To solve the above described problems, a first structure of anintegrated circuit device of the present invention includes: a firstinsulating film; a layer including a thin film circuit formed over onesurface of the first insulating film; a second insulating film formedover the thin film circuit; an electrode formed over the secondinsulting film and electrically connected to the thin film circuit; aresin film formed over the electrode; and a conductive film formedadjacent to the other surface of the first insulating film andelectrically connected to the electrode.

Further, the conductive film is electrically connected to the electrodethrough a hole formed in the first insulating film, the layer includingthe thin film circuit, and the second insulating film.

Furthermore, the integrated circuit device of the present invention mayhave a hole formed in the first insulating film, the layer including thethin film circuit, the second insulating film, the electrode, and theresin film. In this case, the conductive film is electrically connectedto the electrode through part of the hole formed in the first insulatingfilm, the layer including the thin film circuit, and the secondinsulating film.

A second structure of an integrated circuit device of the presentinvention includes: a first insulating film, a layer including a thinfilm circuit formed over one surface of the first insulating film; asecond insulating film formed over the thin film circuit; an electrodeformed over the second insulating film and electrically connected to thethin film circuit; a third insulating film formed over the electrode;and a conductive film formed adjacent to the other surface of the firstinsulating film and electrically connected to the electrode.

A third structure of an integrated circuit device of the presentinvention includes: a substrate with a thickness of 100 μm or less; afirst insulating film formed over one surface of the substrate; a layerincluding a thin film circuit formed over the first insulating film; asecond insulating film formed over the thin film circuit; an electrodeformed over the second insulating film and electrically connected to thethin film circuit; a third insulating film formed over the electrode;and a conductive film formed adjacent to the other surface of thesubstrate and electrically connected to the electrode.

Further, the conductive film is electrically connected to the electrodethrough a hole formed in the first insulating film, the layer includingthe thin film circuit, and the second insulating film.

Furthermore, the integrated circuit device of the present invention mayhave a hole formed in the first insulating film, the layer including thethin film circuit, the second insulating film, the electrode, and thethird insulating film. In this case, the conductive film is electricallyconnected to the electrode through part of the hole formed in the firstinsulating film, the layer including the thin film circuit, and thesecond insulating film.

In each of the above described first and second structures of theintegrated circuit device of the present invention, the thin filmcircuit formed in the layer including the thin film circuit has one or aplurality of elements selected from a thin film transistor, a resistor,a capacitor, and an inductor.

In another aspect of the present invention, a method for manufacturingan integrated circuit device having the first structure as describedabove, includes the steps of: forming a stacked body, which includes afirst insulating film, a thin film circuit formed over one surface ofthe first insulating film, a second insulating film formed over the thinfilm circuit, an electrode formed over the second insulating film andelectrically connected to the thin film circuit, and a resin film formedover the electrode; forming a conductive film adjacent to the othersurface of the first insulating film included in the stacked body to beoverlapped with the electrode; and irradiating the conductive film witha laser.

In another aspect of the present invention, a method for manufacturingan integrated circuit device having the second structure as describedabove, includes the steps of: forming a stacked body, which includes afirst insulating film, a thin film circuit formed over one surface ofthe first insulating film, a second insulating film formed over the thinfilm circuit, an electrode formed over the second insulating film andelectrically connected to the thin film circuit, and a third insulatingfilm formed over the electrode; forming a conductive film adjacent tothe other surface of the first insulating film included in the stackedbody to be overlapped with the electrode; and irradiating the conductivefilm with a laser.

A method for manufacturing an integrated circuit device of the presentinvention includes the steps of: forming a stacked body, which includesa first substrate with a thickness of 100 μm or less, a first insulatingfilm formed over the first substrate, a thin film circuit formed overone surface of the first insulating film, a second insulating filmformed over the thin film circuit, an electrode formed over the secondinsulating film and electrically connected to the thin film circuit, athird insulating film formed over the electrode, and a second substrateformed over the third insulating film; forming a conductive filmadjacent to the other surface of the first insulating film to beoverlapped with the electrode; and irradiating the conductive film witha laser.

Further, in the above described method for manufacturing an integratedcircuit device of the present invention, the thin film circuit has oneor a plurality of elements selected from a thin film transistor, aresistor, a capacitor, and an inductor.

In an integrated circuit device of the present invention, a conductivefilm is formed adjacent to a layer different from a layer, over which anelectrode being electrically connected to a thin film circuit is formed,to be overlapped with the electrode and the conductive film isirradiated with a laser so as to easily form a conductive film forconnecting to an external portion, which is electrically connected tothe electrode. Further, when the conductive film for connecting to anexternal portion, which is electrically connected to the electrode, isformed by laser irradiation, electric resistance of the electrode to theconductive film for connection can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIGS. 1A to 1C are cross sectional views explaining Embodiment Mode 1;

FIGS. 2A to 2C are cross sectional views explaining Embodiment Mode 1;

FIGS. 3A to 3C are cross sectional views explaining Embodiment Mode 1;

FIGS. 4A to 4C are cross sectional views explaining Embodiment Mode 1;

FIG. 5 is a cross sectional view explaining Embodiment Mode 1;

FIGS. 6A to 6D are cross sectional views explaining Embodiment Mode 2;

FIGS. 7A to 7D are cross sectional views explaining Embodiment Mode 2;

FIGS. 8A to 8D are cross sectional views explaining Embodiment Mode 2;

FIG. 9 is a cross sectional view explaining Embodiment Mode 2;

FIGS. 10A and 10B are diagrams explaining Embodiment Mode 2;

FIGS. 11A and 11C are cross sectional views and FIG. 11B is a crosssection view and a top view explaining Embodiment Mode 3;

FIGS. 12A to 12D are cross sectional views explaining Embodiment Mode 3;

FIGS. 13A to 13D are cross sectional views explaining Embodiment Mode 3;

FIGS. 14A to 14D are cross sectional views explaining Embodiment Mode 4;

FIGS. 15A to 15D are cross sectional views explaining Embodiment Mode 4;

FIGS. 16A to 16D are cross sectional views explaining Embodiment Mode 4;

FIG. 17 is a cross sectional view explaining Embodiment Mode 4;

FIGS. 18A to 18C are cross sectional views explaining Embodiment Mode 5;

FIGS. 19A to 19C are cross sectional views explaining Embodiment Mode 5;

FIGS. 20A to 20C are cross sectional views explaining Embodiment Mode 5;

FIGS. 21A to 21C are cross sectional views explaining Embodiment Mode 5;

FIGS. 22A and 22B are cross sectional views explaining Embodiment Mode5;

FIGS. 23A and 23B are cross sectional views explaining Embodiment Mode5;

FIGS. 24A and 24B are cross sectional views explaining Embodiment Mode1;

FIGS. 25A and 25B are cross sectional views explaining Embodiment Mode1;

FIGS. 26A and 26B are diagrams explaining Embodiment 1;

FIG. 27A is a top view and FIG. 27B is a cross sectional view explainingEmbodiment 2;

FIGS. 28A to 28C are diagrams explaining Embodiment 3;

FIGS. 29A to 29D are diagrams explaining Embodiment 4;

FIGS. 30A to 30E are diagrams explaining Embodiment 5;

FIGS. 31A and 31B are diagrams explaining Embodiment 5;

FIG. 32 is a top view of a conductive film before being irradiated witha laser; and

FIG. 33 is a top view of a conductive film after being irradiated with alaser.

DETAILED DESCRIPTION OF THE INVENTION Embodiment Modes Embodiment Mode 1

This embodiment mode will describe a method for manufacturing anintegrated circuit device in a case of forming a circuit having a thinfilm transistor as a thin film circuit.

First, as shown in FIG. 1A, a separation layer 101 is formed over asubstrate 100. As the separation layer 101, a single layer or a stackedlayer is formed using an element selected from tungsten (W), molybdenum(Mo), titanium (Ti), tantalum (Ta), niobium (Nb), nickel (Ni), cobalt(Co), zirconium (Zr), zinc (Zn), ruthenium (Ru), rhodium (Rh), palladium(Pd), osmium (Os), iridium (Ir), and silicon (Si); or an alloy materialor a compound material mainly containing the element, by plasma CVD,sputtering, or the like. A crystalline structure of a layer containingsilicon may be any one of an amorphous structure, a microcrystallinestructure, and a polycrystalline structure.

As the substrate 100, a quartz substrate, a semiconductor substrate, aglass substrate, a metal substrate, or the like may be used.

In a case where the separation layer 101 has a single layer structure, alayer containing any of tungsten; molybdenum; a mixture of tungsten andmolybdenum; tungsten oxide; tungsten oxynitride; tungsten nitride oxide;molybdenum oxide; molybdenum oxynitride; molybdenum nitride oxide; oxideof a mixture of tungsten and molybdenum; oxynitride of a mixture oftungsten and molybdenum; and nitride oxide of a mixture of tungsten andmolybdenum, is preferably formed. Note that the mixture of tungsten andmolybdenum corresponds to an alloy of tungsten and molybdenum, forexample.

In a case where the separation layer 101 has a stacked layer structure,a layer containing tungsten, molybdenum, or a mixture of tungsten andmolybdenum is preferably formed as a first layer; and a layer containingtungsten oxide, molybdenum oxide, oxide of a mixture of tungsten andmolybdenum, tungsten oxynitride, molybdenum oxynitride, or oxynitride ofa mixture of tungsten and molybdenum is preferably formed as a secondlayer.

When the separation layer 101 is formed to have a stacked layerstructure in such a manner, a stacked layer structure of a metal filmand a metal oxide film is preferably used. As examples of a method forforming a metal oxide film, a method by which a metal oxide film isdirectly formed by sputtering; a method by which a surface of a metalfilm formed over the substrate 100 is oxidized by heat treatment orplasma treatment under an oxygen atmosphere to form a metal oxide film;and the like can be given. Preferably, a metal oxide film is formed on asurface of a metal film by performing high-density plasma treatment tothe surface of the metal film under an atmosphere containing oxygen. Forexample, when a tungsten film is formed by sputtering as a metal film,the tungsten film is subjected to the high-density plasma treatment,making it possible to form a metal oxide film made from tungsten oxideon a surface of the tungsten film.

As the metal film, a film formed using an element selected from titanium(Ti), tantalum (Ta), niobium (Nb), nickel (Ni), cobalt (Co), zirconium(Zr), zinc (Zn), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium(Os), and iridium (Ir); or an alloy material or a compound materialmainly containing the element, can be used, in addition to the abovedescribed tungsten (W), molybdenum (Mo).

In this specification, the “high-density plasma treatment” indicatestreatment in which electron density of plasma is 1×10¹¹ cm⁻³ or more and1×10¹³ cm⁻³ or less, and an electron temperature of plasma is 0.5 eV ormore and 1.5 eV or less. Since the electron temperature in the vicinityof an object (which corresponds to a metal film here) formed over asubstrate is low while the electron density of plasma is high, damagedue to plasma to the substrate can be prevented. Further, since theelectron density of plasma is high as 1×10¹¹ cm⁻³ or more, a dense filmhaving an oxide film with a uniform thickness, which is formed byoxidation treatment, can be formed. Furthermore, the electrontemperature of plasma is low as 1.5 eV or less, and therefore, oxidationtreatment can be performed at a lower temperature as compared withnormal plasma treatment or thermal oxidation. For example, even whenplasma treatment is performed at a temperature lower than a strain pointof a glass substrate by 100° C. or more (for example, 250 to 550° C.),plasma oxidation treatment can be sufficiently performed. Note that as afrequency for generating plasma, a microwave (2.45 GHz) is used.Further, potential of plasma is low as 5 V or less so that excessivedissociation of molecules of a raw material can be suppressed.

As an atmosphere containing oxygen, a mixed gas of oxygen (O₂) ordinitrogen monoxide (N₂O) and a rare gas, or a mixed gas of oxygen (O₂)or dinitrogen monoxide (N₂O), a rare gas, and hydrogen (H₂) can be used.As the rare gas, argon (Ar), xenon (Xe), krypton (Kr), and the like canbe given. Further, a pressure ratio of respective gases contained in themixed gas may be appropriately determined. A metal oxide film formedunder this condition becomes a film containing a rare gas element. Sincethe electron temperature is low (1.5 eV or less) and the electrondensity is high (1.0×10¹¹ cm⁻³ or more) in the plasma condition, a metaloxide film can be formed at a low temperature with extremely less plasmadamage.

Note that prior to forming the separation layer 101, an insulating filmsuch as a silicon oxide film, a silicon nitride film, a siliconoxynitride film, or a silicon nitride oxide film may be formed over thesubstrate 100 and then the separation layer 101 may be formed over theinsulating film. By providing such an insulating film between thesubstrate 100 and the separation layer 101, an impurity contained in thesubstrate 100 can be prevented from intruding into an upper layer. Inaddition, in a subsequent laser irradiation step, the substrate 100 canbe prevented from being etched. Note that a silicon oxynitride film anda silicon nitride oxide film are separately used here. The siliconoxynitride film contains larger amounts of oxygen than nitrogen whereasthe silicon nitride oxide film contains larger amounts of nitrogen thanoxygen.

Next, as shown in FIG. 1B, a first insulating film 102 is formed to bein contact with the separation layer 101. The first insulating film 102serves as a base film. The first insulating film 102 is formed usingsilicon oxide, silicon nitride, silicon oxide containing nitrogen,silicon nitride containing oxygen, or the like by plasma CVD,sputtering, or the like.

As shown in FIG. 1C, a layer 104 including circuits 103 having thin filmtransistors is formed over the first insulating film 102 by a knownmethod. As the layer 104 including the circuits 103 having the thin filmtransistors, for example, a plurality of thin film transistors, a secondinsulating film 110 covering the plurality of thin film transistors, andsource and drain wirings 111 being in contact with the second insulatingfilm 110 and connecting to source regions and drain regions of theplurality of thin film transistors, are formed. A single thin filmtransistor includes an island-like semiconductor film 107, a gateinsulating film 108, a gate electrode 109 provided with a sidewall, andthe like. As the circuits 103 including the thin film transistors,circuits each having a structure, which includes an N-channel thin filmtransistor 105 and a P-channel thin film transistor 106, is shown as anexample in FIG. 1C; however, the present invention is not limited tosuch a structure. Further, FIG. 1C shows an example in which top-gatethin film transistors each having a gate electrode provided with asidewall and an LDD region (a low concentration impurity region) areformed as the N-channel thin film transistors 105 and top-gate thin filmtransistors each having a gate electrode provided with a sidewall isformed as the P-channel thin film transistors 106; however, thestructures of the thin film transistors are not limited thereto. A knownstructure of a thin film transistor such as a thin film transistorhaving no LDD region (no low concentration impurity region), abottom-gate thin film transistor, or a thin film transistor having asilicide region, is applicable.

An example of a method for forming the layer 104 including the circuits103 having the thin film transistors will be described in detail below.

First, an amorphous semiconductor film is formed over the firstinsulating film 102. The amorphous semiconductor film is formed bysputtering or various types of CVD such as plasma CVD. Subsequently, theamorphous semiconductor film is crystallized to form a crystallinesemiconductor film. As a crystallization method, laser crystallization,thermal crystallization using RTA or an annealing furnace, thermalcrystallization using a metal element for promoting crystallization,thermal crystallization using a metal element for promotingcrystallization with laser crystallization, or the like can be used.Thereafter, the obtained crystalline semiconductor film is patternedinto a desired shape to form island-like semiconductor films 107. Notethat the separation layer 101, the first insulating film 102, and theamorphous semiconductor film can be successively formed without beingexposed to atmospheric air.

An example of a method for forming a crystalline semiconductor film willbe briefly described below. As a method for crystallizing an amorphoussemiconductor film, laser crystallization, thermal crystallization usingRTA or an annealing furnace, thermal crystallization using a metalelement for promoting crystallization, thermal crystallization using ametal element for promoting crystallization with laser crystallization,or the like can be given. Further, as other crystallization method,crystallization may be performed by generating thermal plasma byapplying DC bias and making the thermal plasma affect to a semiconductorfilm.

When employing laser crystallization, a continuous wave laser beam (CWlaser beam) or a pulsed laser beam (pulse laser beam) can be used. As ausable laser beam, a beam oscillated from one or plural kinds of a gaslaser such as an Ar laser, a Kr laser, or an excimer laser; a laserusing, as a medium, single crystalline YAG, YVO₄, forsterite (Mg₂SiO₄),YAlO₃, or GdVO₄ or polycrystalline (ceramic) YAG, Y₂O₃, YVO₄, YAlO₃, orGdVO₄ doped with one or more of Nd, Yb, Cr, Ti, Ho, Er, Tm, and Ta as adopant; a glass laser; a ruby laser; an alexandrite laser; a Ti:sapphire laser; a copper vapor laser; and a gold vapor laser, can beused. The amorphous semiconductor film is irradiated with a laser beamhaving a fundamental wave of such a laser or a second to a fourthharmonic of a fundamental wave thereof to obtain a crystal with a largegrain size. For instance, the second harmonic (532 nm) or the thirdharmonic (355 nm) of an Nd:YVO₄ laser (fundamental wave of 1,064 nm) canbe used. In this case, energy density of about 0.01 to 100 MW/cm²(preferably, 0.1 to 10 MW/cm²) is required for a laser. The scanningrate is set to be about 10 to 2,000 cm/sec to irradiate thesemiconductor film with the laser.

Note that each laser using, as a medium, single crystalline YAG, YVO₄,forsterite (Mg₂SiO₄), YAlO₃, or GdVO₄ or polycrystalline (ceramic) YAG,Y₂O₃, YVO₄, YAlO₃, or GdVO₄ doped with one or more of Nd, Yb, Cr, Ti,Ho, Er, Tm, and Ta as a dopant; an Ar ion laser; and a Ti: sapphirelaser, can continuously oscillate. Further, pulse oscillation thereofcan be performed with an oscillation frequency of 10 MHz or more bycarrying out Q switch operation or mode synchronization. When a laserbeam is oscillated with an oscillation frequency of 10 MHz or more, asemiconductor film is irradiated with a next pulse during a period wherethe semiconductor film is melted by the laser beam and then issolidified. Therefore, differing from a case of using a pulsed laserwith a low oscillation frequency, a solid-liquid interface can becontinuously moved in the semiconductor film so that crystal grains,which continuously grow toward a scanning direction, can be obtained.

When an amorphous semiconductor film is crystallized by using acontinuous wave laser or a laser beam which is oscillated at a frequencyof 10 MHz or more, a surface of the crystallized semiconductor film canbe planarized. As a result, the gate insulating film 108, which will beformed later, can be formed thinly. In addition, this contributes to theimprovement the breakdown voltage of the gate insulating film 108.

When ceramic (polycrystal) is used for the medium, the medium can beformed to have a free shape for a short time at low cost. When using asingle crystal, a columnar medium with several mm in diameter andseveral tens of mm in length is usually used. Meanwhile, in the case ofusing the ceramic, a medium bigger than the case of using the singlecrystal can be formed.

A concentration of a dopant such as Nd or Yb in a medium, which directlycontributes to light emission, cannot be changed largely in both casesof the single crystal and the polycrystal, and therefore, there is alimitation in improvement in output of a laser by increasing theconcentration of the dopant to some extent. However, in the case of theceramic, the size of the medium can be significantly increased ascompared with the case of the single crystal, and therefore, drasticimprovement in output of a laser can be expected.

Further, in the case of the ceramic, a medium with a parallelepipedshape or a rectangular parallelepiped shape can be easily formed. In acase of using a medium having such a shape, when oscillated light ismade travel in a zig-zag manner inside the medium, a path of theoscillated light can be made long. Therefore, amplitude is increased anda laser beam can be oscillated at high output. Furthermore, a crosssection of a laser beam emitted from a medium having such a shape has aquadrangular shape, and therefore, as compared with a laser beam with acircular shape, the laser beam with the quadrangular shape in the crosssection is more favorably shaped into a linear beam. By shaping a laserbeam emitted in the above described manner using an optical system, alinear beam with 1 mm or less in length of a short side and several mmto several m in length of a long side can be easily obtained. Inaddition, when a medium is uniformly irradiated with excited light, alinear beam is emitted with a uniform energy distribution in a long sidedirection.

When a semiconductor film is irradiated with this linear beam, thesemiconductor film can be uniformly annealed. In a case where uniformannealing is required from one end to the other end of the linear beam,an ingenuity in which slits are provided in the both ends of the linearbeam so as to shield an attenuated portion of energy from light, or thelike may be performed.

When a semiconductor film is annealed by using the thus obtained linearbeam with uniform intensity and a semiconductor device is manufacturedby using this semiconductor film, a characteristic of the semiconductordevice can be made favorable and uniform.

As thermal crystallization using a metal element for promotingcrystallization, an example of a specific method will be given. Afterkeeping a solution containing nickel, which is a metal element forpromoting crystallization, over an amorphous semiconductor film, theamorphous semiconductor film is subjected to dehydrogenation treatment(500° C. for one hour) and thermal crystallization treatment (550° C.for four hours) so as to form a crystalline semiconductor film.Thereafter, the crystalline semiconductor film is irradiated with alaser beam if required, and then, the crystalline semiconductor film ispatterned by photolithography to form the island-like semiconductorfilms 107.

The thermal crystallization using a metal element for promotingcrystallization has advantages of being capable of crystallizing anamorphous semiconductor film at a low temperature for a short time andaligning a direction of crystals; however, the thermal crystallizationhas drawbacks that off current is increased due to a residue of themetal element in the crystalline semiconductor film and characteristicsof the crystalline semiconductor film are not stabilized. Therefore, itis preferable to form an amorphous semiconductor film serving as agettering site over the crystalline semiconductor film. Since theamorphous semiconductor film, which becomes the gettering site, isnecessary to contain an impurity element such as phosphorus or argon,the amorphous semiconductor film is preferably formed by sputtering bywhich the amorphous semiconductor film can contain argon at a highconcentration. Thereafter, heat treatment (RTA, thermal annealing usingan annealing furnace, or the like) is performed to disperse the metalelement to the amorphous semiconductor film. Subsequently, the amorphoussemiconductor film containing the metal element is removed. By carryingout such the gettering process, the amount of the metal elementcontained in the crystalline semiconductor film can be reduced or themetal element can be removed.

Next, the gate insulating film 108 is formed to cover the island-likesemiconductor films 107. As the gate insulating film 108, a single layeror a stacked layer is formed by using a film containing silicon oxide orsilicon nitride by sputtering or various types of CVD such as plasmaCVD. Specifically, the gate insulating film 108 is formed by using asingle layer of a film containing silicon oxide, a film containingsilicon oxynitride, or a film containing silicon nitride oxide, or byappropriately stacking these films. Alternatively, the island-likesemiconductor films 107 may be subjected to the above describedhigh-density plasma treatment under an atmosphere containing oxygen,nitrogen, or both of oxygen and nitrogen to oxidize or nitride eachsurface of the island-like semiconductor films 107 so as to form thegate insulating film. The gate insulating film formed by thehigh-density plasma treatment has superior uniformity in film thicknessand film quality as compared with a film formed by CVD or sputtering. Inaddition, a dense film can be formed as the gate insulating film by thehigh-density plasma treatment. As an atmosphere containing oxygen, amixed gas of oxygen (O₂), nitrogen dioxide (NO₂) or dinitrogen monoxide(N₂O), and a rare gas; or a mixed gas of oxygen (O₂), nitrogen dioxide(NO₂) or dinitrogen monoxide (N₂O), a rare gas, and hydrogen (H₂); canbe used. Further, as an atmosphere containing nitrogen, a mixed gas ofnitrogen (N₂) or ammonia (NH₃) and a rare gas; or a mixed gas ofnitrogen (N₂) or ammonia (NH₃), a rare gas, and hydrogen (H₂), can beused. Each surface of the island-like semiconductor films 107 can beoxidized or nitrided by oxygen radical (which contains OH radical insome cases) or nitrogen radical (which contains NH radical in somecases) generated by high-density plasma.

When the gate insulating film 108 is formed by the high-density plasmatreatment, an insulating film with a thickness of 1 to 20 nm, andtypically, 5 to 10 nm, is formed over the island-like semiconductorfilms 107. A reaction in this case is a solid-phase reaction, andtherefore, interface state density between the insulating film and theisland-like semiconductor films 107 can be extremely reduced. Further,since the island-like semiconductor films 107 are directly oxidized ornitrided, variations in thickness of the gate insulating film 108 can besuppressed significantly and ideally. Furthermore, since strongoxidation is not generated in a crystal grain boundary of crystallinesilicon, an extremely preferable state is made. That is, when thesurface of the semiconductor films is subjected to solid-phase oxidationby the high-density plasma treatment shown here, an insulating film withlow interface state density and good uniformity can be formed withoutgenerating abnormal oxidation reaction in a crystal grain boundary.

Note that, as the gate insulating film 108, only an insulating filmformed through the high-density plasma treatment may be used.Alternatively, the insulating film formed through the high-densityplasma treatment and another insulating film formed using silicon oxide,silicon nitride containing oxygen, or silicon oxide containing nitrogenby CVD utilizing plasma or a thermal reaction may be stacked to form thegate insulating film 108. In either case, when a transistor partly orentirely including an insulating film formed by high-density plasma isformed, variations in characteristics can be reduced.

Further, the crystalline semiconductor film, which is formed bycrystallizing the amorphous semiconductor film by irradiation of acontinuous wave laser beam or a laser beam oscillated at a frequency of10 MHz or more while scanning the amorphous semiconductor film with thelaser beam in one direction, has a characteristic that crystals grow ina scanning direction of the laser beam. Therefore, when a transistor isdisposed such that the scanning direction corresponds to a channellength direction (a direction of flowing carries when a channel regionis formed), and the gate insulating film 108 formed by the high-densityplasma treatment is combined with the transistor, a transistor withlesser variations in characteristics and high electron field-effectmobility can be obtained.

Next, gate electrodes 109 are formed over the gate insulating film 108.The gate electrodes 109 may be formed by sputtering or various types ofCVD such as plasma CVD. Further, the gate electrodes 109 can be formedby using an element selected from tantalum (Ta), tungsten (W), titanium(Ti), molybdenum (Mo), aluminum (Al), copper (Cu), chromium (Cr),niobium (Nb), and the like; or an alloy material or a compound materialmainly containing these elements. Further, the gate electrodes can beformed by using a semiconductor material typified by polycrystallinesilicon doped with an impurity element such as phosphorus.

Next, impurity elements are selectively added to the island-likesemiconductor films 107 by ion doping or ion implantation to formN-channel thin film transistors 105 and P-channel thin film transistors106. Note that in FIG. 1C, LDD regions (low concentration impurityregions) are formed using insulating films (sidewalls) in contact with aside surface of each gate electrode 109 in each of the N-channel thinfilm transistors 105. As an impurity element imparting N-typeconductivity used for forming the N-channel thin film transistors 105,an element belonging to Group 15 of the periodic table may be used, andfor example, phosphorus (P) or arsenic (As) is used. Further, as animpurity element imparting P-type conductivity used for forming theP-channel thin film transistors 106, an element belonging to Group 13may be used, and for example, boron (B) is used.

After completing the N-channel thin film transistors 105 and the P-typethin film transistors 106 through the above described steps, heattreatment for recovering crystallinity of the semiconductor films oractivating the impurity elements added to the semiconductor films, maybe performed. Further, after performing the heat treatment, the exposedgate insulating film 108 may be subjected to high-density plasmatreatment under an atmosphere containing hydrogen so that a surface ofthe gate insulating film 108 may contain hydrogen. This is because thehydrogen can be utilized when performing a step of hydrogenating thesemiconductor films later. Further, by performing high-density plasmatreatment under an atmosphere containing hydrogen while heating thesubstrate at 350 to 450° C., hydrogenation of the semiconductor filmscan be performed. Further, as the atmosphere containing hydrogen, amixed gas of hydrogen (H₂) or ammonia (NH₃) and a rare gas (for example,argon (Ar)) can be used. When a mixed gas of ammonia (NH₃) and a raregas (for example, argon (Ar)) is used as the atmosphere containinghydrogen, the surface of the gate insulating film 108 can behydrogenated and nitrided at the same time.

Then, a second insulating film 110 is formed to cover the plurality ofthin film transistors. The second insulating film 110 is formed using asingle layer or a stacked layer made from an inorganic material such assilicon oxide or silicon nitride; an organic material such as polyimide,polyamide, benzocychlobutene, acrylic, or epoxy; siloxane; or the like,by an SOG technique, a droplet discharging method, or the like. In thisspecification, siloxane has a skeleton structure including silicon(Si)-oxygen (O) bonds and an organic group containing at least hydrogen(for example, an alkyl group, aromatic hydrocarbon, or the like) is usedas a substituent. Further, as the substituent, a fluoro group may beused, or both of an organic group containing at least hydrogen and afluoro group may be used. For example, in a case where the secondinsulating film 110 has a three layer structure, a film mainlycontaining silicon oxide may be formed as a first insulating film, afilm mainly containing a resin may be formed as a second insulatingfilm, and a film mainly containing silicon nitride may be formed as athird insulating film. Further, in a case where the second insulatingfilm 110 has a single layer structure, a silicon nitride film or asilicon nitride film containing oxygen may be formed. In this case, itis preferable that by performing high-density plasma treatment under anatmosphere containing hydrogen with respect to the silicon nitride filmor the silicon nitride film containing oxygen, hydrogen be contained ina surface of the silicon nitride film or the silicon nitride filmcontaining oxygen. This is because when performing a hydrogenation stepof the island-like semiconductor films 107 later, this hydrogen can beutilized. Further, by performing high-density plasma treatment under anatmosphere containing hydrogen while heating the substrate at 350 to450° C., hydrogenation of the semiconductor films can be performed. Notethat, as the atmosphere containing hydrogen, a mixed gas of hydrogen(H₂) or ammonia (NH₃) and a rare gas (for example, argon (Ar)) can beused. When a mixed gas of ammonia (NH₃) and a rare gas (for example,argon (Ar)) is used as the atmosphere containing hydrogen, the surfaceof the gate insulating film 108 can be hydrogenated and nitrided at thesame time.

Note that, prior to forming the second insulating film 110, heattreatment for recovering crystallinity of the semiconductor films,activating the impurity elements added to the semiconductor films, orhydrogenating the semiconductor films, is preferably performed. The heattreatment preferably employs thermal annealing, laser annealing, RTA, orthe like. For example, in order to activate the impurity elements,thermal annealing at 500° C. or more is preferably performed. Further,in order to hydrogenate the semiconductor films, thermal annealing at350 to 450° C. may be performed.

Next, the second insulating film 110 and the gate insulating film 108are etched by photolithography to form contact holes by which theisland-like semiconductor films 107 are exposed. Subsequently, aconductive film is formed to fill the contact holes. The conductive filmis patterned to form source or drain wirings 111.

The source or drain wirings 111 are formed by using a conductive filmmainly containing aluminum (Al) by sputtering, various types of CVD suchas plasma CVD, or the like. The conductive film mainly containingaluminum (Al) corresponds to a material mainly containing aluminum,which also contains nickel, or an alloy material mainly containingaluminum, which also contains nickel and one or both of carbon andsilicon, for example. Since the conductive film mainly containingaluminum generally has a drawback of a poor heat resistance property, anupper surface and a lower surface of the conductive film mainlycontaining aluminum are preferably covered with barrier films. Thebarrier films indicate films having a function of suppressing heroic ofthe conductive film mainly containing aluminum or improving a heatresistance property. As a material having such a function, chromium,tantalum, tungsten, molybdenum, titanium, silicon, and nickel, ornitride of these elements can be given. As an example of a structure ofeach of the source or drain wirings 111, a structure in which a titaniumfilm, an aluminum film, and another titanium film are sequentiallystacked from a substrate side, can be given. Since titanium is anelement having a high reducing property, even when a thin oxide film isnaturally formed on the crystalline semiconductor film, the oxide filmnaturally formed can be reduced by the titanium so that the titaniumfilm can be well-contacted to the crystalline semiconductor film.Further, the titanium film formed between the crystalline semiconductorfilm and the aluminum film, is preferably subjected to high-densityplasma treatment under an atmosphere containing nitrogen to nitride asurface of the titanium film. In a condition of the high-density plasmatreatment, electron density of plasma is 1×10¹¹ cm⁻³ or more and 1×10¹³cm⁻³ or less, and an electron temperature of plasma is 0.5 eV or moreand 1.5 eV or less. As the atmosphere containing nitrogen, a mixed gasof N₂ or NH₃ and a rare gas, or a mixed gas of N₂ or NH₃, a rare gas,and H₂ can be used. Nitriding the surface of the titanium film makes itpossible to prevent alloying of titanium and aluminum and preventaluminum from dispersing in the crystalline semiconductor film throughthe titanium film in a step of heat treatment or the like, which will beperformed later. Note that an example of sandwiching the aluminum filmwith the titanium films is described here, and this is the same for acase of using chromium films, tungsten films, or the like instead of thetitanium films. More preferably, formation of the titanium film,nitriding treatment of the surface of the titanium film, formation ofthe aluminum film, and formation of another titanium film aresuccessively carried out by using a multi-chamber apparatus withoutexposing these films to atmospheric air.

According to the above described steps, the layer 104 including thecircuits 103 having the thin film transistors is formed.

Next, as shown in FIG. 2A, a third insulating film 112 is formed overthe layer 104 including the circuits 103 having the thin filmtransistors. Subsequently, electrodes 113, which are electricallyconnected to wirings of the circuits 103 including the thin filmtransistors, are formed over the third insulating film 112 by using ametal film or the like. As the electrodes 113, a TiN film is formed bysputtering here.

The third insulating film 112 is formed using a single layer or astacked layer made from an inorganic material such as silicon oxide,silicon nitride, silicon oxynitride, or silicon nitride oxide; anorganic material such as polyimide, polyamide, benzocychlobutene,acrylic, or epoxy; siloxane, or the like, by a known method.

Further, although the electrodes 113 are formed to be connected to thesource or drain wirings of the thin film transistors in FIG. 2A, thepresent invention is not limited to this case. An electrode may beformed at a portion to be electrically connected to an external circuitin each thin film circuit.

After forming the electrodes 113, a resin film 114 is formed over theelectrodes 113 to have a thickness of 20 to 30 μm as shown in FIG. 2B. Aresin material such as a heat curing resin, a UV (ultraviolet) curingresin, or a thermoplastic resin is applied over the electrodes 113 byscreen printing, and then baked to form the resin film here.

Subsequently, as shown in FIG. 2C, the substrate is irradiated with alaser with a wavelength in an ultraviolet region (hereinafter, referredto as a UV laser) to form opening portions 115 and 116 as shown in FIG.3A. In this case, by forming the opening portions 115 and 116, theseparation layer 101 is partly removed so that a stacked body 118including the first insulating film 102, the layer 104 including thecircuits 103 having the thin film transistors, the third insulating film112, the electrodes 113, and the resin film 114 can be easily separatedfrom the substrate 100. The stacked body is separated from the substrateat a boundary between an interior portion of the separation layer 101 orthe separation layer 101 and the first insulating film 102.

Further, the UV laser is used in this embodiment mode; however, a typeof a laser used in the present invention is not particularly limited solong as it can form the opening portions 115 and 116. A laser includes alaser medium, an excitation source, and a resonator. When lasers areclassified based on mediums, there as a gas laser, a liquid laser, and asolid laser. When lasers are classified based on characteristics ofoscillation, there are a free electron laser, a semiconductor laser, andan X-ray laser. Any laser can be used in the present invention. Notethat a gas laser or a solid laser is preferably used. More preferably, asolid laser is used.

As a gas laser, there are a helium-neon laser, a carbon dioxide gaslaser, an excimer laser, and an argon ion laser. As an excimer laser,there are a rare gas excimer laser and a rare gas halide laser. A raregas excimer laser gives oscillations generated by three kinds of excitedmolecules of argon, krypton, and xenon. As an argon ion laser, there area rare gas ion laser and a metal vapor ion laser.

As a liquid laser, there are an inorganic liquid laser, an organicchelate laser, and a dye laser. Each of the inorganic liquid laser andthe organic chelate laser utilizes a rare earth ion such as neodymium,which is used for a solid laser, as a laser medium.

A laser medium used for a solid laser is a solid body doped with activespecies providing laser action. The solid body indicates a crystal orglass. The crystal indicates YAG (an yttrium, aluminum, garnet crystal),YLF, YVO₄, YAlO₃, sapphire, ruby, or alexandrite. Further, the activespecies providing laser action is a trivalent ion (Cr³⁺, Nd³⁺, Yb³⁺,Tm³⁺, Ho³⁺, Er³⁺, Ti³⁺, etc.), for example.

Further, when using ceramic (a polycrystal), a medium can be formed tohave a free shape for a short time at low cost. When using a singlecrystal, generally, a columnar medium with a diameter of several mm anda length of several tens of mm is used. In a case of using ceramic (apolycrystal), a medium with larger size can be formed. A concentrationof a dopant such as Nd or Yb in a medium, which directly contributes tolight emission, cannot be changed largely in both cases of the singlecrystal and the polycrystal, and therefore, there is a limitation inimprovement in output of a laser by increasing the concentration of thedopant to some extent. However, in the case of the ceramic, the size ofa medium can be significantly increased as compared with the case of thesingle crystal, and therefore, drastic improvement in output of a lasercan be expected. Further, in the case of the ceramic, a medium with aparallelepiped shape or a rectangular parallelepiped shape can be easilyformed. In a case of using a medium having such a shape, when oscillatedlight is made travel in a zigzag manner inside the medium, a path of theoscillated light can be made long. Therefore, amplitude is increased anda laser beam can be oscillated at high output. Furthermore, a crosssection of a laser beam emitted from a medium having such a shape, has aquadrangular shape, and therefore, as compared with a laser beam with acircular shape, the laser beam with the quadrangular shape in crosssection have an advantage to be shaped into a linear beam. By shaping alaser beam emitted in the above described manner using an opticalsystem, a linear beam with 1 mm or less in length of a short side andseveral mm to several m in length of a long side can be easily obtained.In addition, when a medium is uniformly irradiated with excited light, alinear beam is emitted with a uniform energy distribution in a long sidedirection. When a semiconductor film is irradiated with this linearbeam, the semiconductor film can be uniformly annealed. In a case whereuniform annealing is required from one end to the other end of thelinear beam, an ingenuity in which slits are provided in the both endsof the linear beam so as to shield an attenuated portion of energy fromlight, or the like may be performed

As a laser used in the present invention, either a continuous wave laserbeam (a CW laser beam) or a pulsed oscillation laser beam (a pulsedlaser beam) can be used. Further, laser irradiation conditions such as afrequency, power density, energy density, and a beam profile arearbitrarily controlled in consideration of thicknesses, materials or thelike of the first insulating film 102, the layer 104 including thecircuits 103 having the thin film transistors, the third insulating film112, the electrodes 113, and the resin film 114.

In order to separate the stacked body 118 including the first insulatingfilm 102, the layer 104 including the circuits 103 having the thin filmtransistors, the third insulating film 112, the electrodes 113, and theresin film 114 from the substrate 100, a first film 117 is attached to asurface of the resin film 114 and the first film 117 is pulled in adirection of an arrow as shown in FIG. 3B so that the stacked body 118including the first insulating film 102, the layer 104 including thecircuits 103 having the thin film transistors, the third insulating film112, the electrodes 113, and the resin film 114 is separated from thesubstrate 100. In this case, the substrate 100 and the stacked body 118are separated from each other at a boundary between an interior portionof the separation layer 101 or the separation layer 101 and the firstinsulating film 102. In the stacked body 118 separated from thesubstrate 100, the first insulating film 102 becomes an outermostsurface. The resin film 114 secures strength when separating thesubstrate 100 and the stacked body 118 from each other by pulling thefirst film 117. The stacked body 118 can be prevented from breaking inthis step by the resin film 114.

The first film 117 has a structure in which an adhesive layer isprovided on a base film made from a resin material. For example, a hotmelt film, a UV (ultraviolet) separating film, a heat separating film,and the like can be given. As a material used for the base film,polyester, PET (polyethylene terephthalate), PEN (polyethylenenaphthalate), and the like can be given.

A hot melt film has a structure in which over a base film, an adhesivelayer made from a resin having a softening point, which is lower thanthat of the base film, is formed. A polyethylene resin, polyester, EVA(ethylene vinyl acetate), and the like can be given for a material usedfor the adhesive layer. Further, a UV (ultraviolet) separating film hasa structure in which an adhesive layer made from a resin material whoseadhesion is weakened by being irradiated with a UV (ultraviolet) ray, isformed over a base film. A heat separating film has a structure in whichan adhesive layer made from a resin material whose adhesion is weakenedby heating is formed over a base film.

Then, as shown in FIG. 3C, conductive films 119 each having a thicknessof 1 μm to several tens of μm, and preferably, 10 μm to 20 μm, areformed over a surface of the first insulating film 102 (a back surfaceof a thin film circuit), i.e., the surface of the insulating film 102 onwhich the layer 104 including the circuits 103 having the thin filmtransistors is not formed, such that the conductive films are overlappedwith the electrodes 113. The conductive films 119 may be formed using aconductive material such as an Au paste, an Ag paste, a Cu paste, an Nipaste, or an Al paste, solder, or the like by screen printing, forexample. When each thickness of the conductive films 119 is 0.1 μnm orless, the conductive films cannot be electrically connected to theelectrodes 113 in a subsequent step because of their excessive thinthickness.

Then, as shown in FIG. 4A, the conductive films 119 are irradiated withlaser beams. In this case, output of a laser is adjusted such that theconductive films 119 are moved to reach the electrodes 113 and the movedconductive films 119 are stopped at the electrodes 113. Laserirradiation is performed by using an Nd:YVO₄ pulse laser with a laserwavelength of 266 nm under conditions of an oscillation frequency of 15kHz and an average output of 3 W. These conditions are typicalconditions and the present invention is not limited thereto. Theconductive films 119 and the electrodes 113 are electrically connectedto one another by the laser irradiation, and hence, a state shown inFIG. 4B is obtained. In FIG. 4B, reference numeral 120 indicates one ofthe conductive films being electrically connected to one electrode 113.

As shown in FIG. 4B, holes are formed in the layer 104 including thecircuits 103 having the thin film transistors and the third insulatingfilm 112 at positions irradiated with the laser beams, and a material ofthe conductive films 119 is moved to the electrodes 113 along side wallsof the holes; therefore, the conductive films 119 are electricallyconnected to the electrodes 113.

An optical micrograph, which is taken from a top surface of a singleconductive film 119 before laser irradiation for electrically connectingthe conductive film 119 to the electrode 113, is shown in FIG. 32. Anoptical micrograph, which is taken from a top surface of the conductivefilm 119 after laser irradiation for electrically connecting theconductive film 119 to the electrode 113, is shown in FIG. 33. Theoptical micrographs shown in FIGS. 32 and 33 are taken at 50-foldmagnification. A circular hole is formed as shown in FIG. 33. Theconductive film 119 is electrically connected to the electrode 113through this hole. Note that the hole for electrically connecting theconductive film 119 to the electrode 113 has the circular shape in FIG.33; however, the shape of the hole is not limited to the circular shape.Further, there are portions that looks like cracks in FIG. 33; however,these portions had been contacted with a probe when measuringresistance, and the portions of the surface of the conductive film 119where had been contacted with the probe, is rubbed and becomes metallic.

Note that an example where the output of the laser is adjusted such thatthe conductive films 119 are moved to reach the electrodes 113 andstopped at the electrodes 113, is shown here. Alternatively, the outputof the laser may be adjusted such that holes passing through the resinfilm 114 and the first film 117 are formed.

By irradiating each portion between the adjacent circuits 103 having thethin film transistors with laser beams as shown in FIG. 4C, the circuits103 having the thin film transistors are individually divided into threeportions 121, 122, and 123 each including a single circuit 103 havingthe thin film transistors. The divided portions 121, 122, and 123 becomeintegrated circuit devices, respectively.

An example where the three circuits 103 having the thin film transistorsare formed over the substrate is described in this embodiment mode;however, the number of the circuits 103 having the thin film transistorsprovided over the substrate is not limited thereto. It goes withoutsaying that the number of the circuit 103 having the thin filmtransistors may be one, two, or three or more.

As described above, integrated circuit devices of the present inventionare formed. A step of forming a semiconductor device by mounting anintegrated circuit device of the present invention obtained above over asubstrate, over which an antenna is formed, will be described below.

As shown in FIG. 24A, a conductive film 723 having a function of anantenna is formed over a substrate 722. An integrated circuit device 726is attached to a surface of the substrate 722 by using a resin 724containing conductive particles 725. By attaching the integrated circuitdevice 726 and the substrate 722 to each other using the resin 724containing the conductive particles 725, connection portions of theconductive film 723 having the function of the antenna are electricallyconnected to connection conductive films provided at a back surface ofthe integrated circuit device 726 through the conductive particles 725.

Then, heat treatment is performed to cure the resin 724 containing theconductive particles 725. When using a heat separating film as the firstfilm 117, the first film 117 can be separated from the resin film 114 bythis heat treatment. A state after separating the first film 117 fromthe resin film 114 is shown in FIG. 24B.

As described above, the integrated circuit device of the presentinvention can be mounted over the substrate over which the antenna isformed. Note that a case where the conductive film having the functionof the antenna and the integrated circuit device are electricallyconnected to each other by using the resin containing the conductiveparticles is described here. Alternatively, as a material forelectrically connecting the conductive film having the function of theantenna to the integrated circuit device, a known material such assolder may be used, in addition to the resin containing the conductiveparticles.

In a case of using solder as a material for electrically connecting theconductive film having the function of the antenna to the integratedcircuit device, heat treatment is also performed to melt the solder.Therefore, when using a heat separating film as the first film 117, thefirst film 117 can be separated from the resin film 114 by the heattreatment.

After mounting the integrated circuit device of the present inventionover the substrate over which the antenna is formed, sealing ispreferably performed. At least one surface of the substrate 722, overwhich the conductive film 723 having the function of the antenna isformed, may be sealed. A case where only one surface of the substrate722, over which the conductive film 723 having the function of theantenna is formed, is sealed will be shown in FIG. 25A. When sealing isperformed, the conductive film having the function of the antenna issealed with a second film 729 having a structure in which an adhesivelayer is provided over a base film. As the second film 729, a hot meltfilm can be given, for example. A hot melt film has a structure in whichover a base film, an adhesive layer made from a resin having a softeningpoint, which is lower than that of the base film, is formed. As amaterial used for the base film, polyester, PET (polyethyleneterephthalate), PEN (polyethylene naphthalate), and the like can begiven. A polyethylene resin, polyester, EVA (ethylene vinyl acetate),and the like can be given as a material used for the adhesive layer.

Further, as shown in FIG. 25B, the substrate 722 over which the antennais formed may be sealed with two films (a second film 727 and a thirdfilm 728). As the second film 727 and the third film 728 shown in FIG.25B, films each having a structure in which an adhesive layer is formedover a base film, may be used.

A case where after separating the first film 117 at the time of heattreatment, the substrate 722 over which the antenna is formed is sealedis described in FIGS. 24A and 24B and FIGS. 25A and 25B Alternatively,the substrate 722 over which the antenna is formed can be sealed whilethe first film 117 is attached to the surface of the resin film 114without separating the first film 117. In this case, a film other than aheat separating film (such as a hot melt film) can be used.

Each of the integrated circuit devices formed in this embodiment modehas a resin film over the circuit having the thin film transistors andthe electrode for electrically connecting to an external portion isprovided adjacent to a back surface of the circuit having the thin filmtransistors. That is, the conductive film being electrically connectedto the circuit having the thin film transistors is provided over asurface of the integrated circuit device, over which the resin film isnot formed. Since the total thickness of the first insulating film andthe layer including the circuit having the thin film transistors isabout 10 μm or less and a thickness of the resin film is about 20 to 30μm, by forming the conductive film being electrically connected to thecircuit having the thin film transistors over the surface of theintegrated circuit device over which the resin film is not formed, theconductive film being electrically connected to the circuit having thethin film transistors can be easily formed as compared to forming itover the resin film side.

Embodiment Mode 2

Although a case where the circuits having the thin film transistors areformed as thin film circuits is described in Embodiment Mode 1, a caseof forming a circuit having a resistor as a thin film circuit will bedescribed in this embodiment mode. Further, although the circuits havingthe thin film transistors are formed as the thin film circuits inEmbodiment Mode 1 and a resistor will be formed as a thin film circuitin this embodiment mode, a case where a circuit having plural kinds ofelements selected from a thin film transistor, a resistor, an inductor,and a capacitor can be implemented in accordance with the presentinvention.

As shown in FIG. 6A, a separation layer 201 is formed over a substrate200, and a first insulating film 202 is formed over the separation layer201. The substrate 200 and the separation layer 201 may be formed usingthe same materials and the same methods described in Embodiment Mode 1,respectively.

Next, as shown in FIG. 6B, a resistive element 204 is formed over thefirst insulating film 202. The resistive element 204 may be formed usingTa₂N, for example. Examples of a shape of the resistive element 204 seenfrom its top surface are shown in FIGS. 10A and 10B. Note that a case offorming a resistive element having the shape shown in FIG. 10A as theresistive element 204 will be described below.

After forming the resistive element 204, a second insulating film 205 isformed over the resistive element 204 as shown in FIG. 6C. Then,openings 206 are formed in the second insulating film 205 as shown inFIG. 6D. The openings 206 are holes through which the resistive element204 is contacted to electrodes, which will be formed later. The openings206 are formed over regions 216 and 217 shown in FIG. 10A. In a casewhere a resistive element having the shape shown in FIG. 10B is formed,the openings 206 may be formed over regions 219 and 220 of FIG. 10B.

After forming the openings 206, electrodes 207 being electricallyconnected to the resistive element 204 are formed over the secondinsulating film 205 as shown in FIG. 7A. The electrodes 207 are formedto be electrically connected to the regions 216 and 217 of FIG. 10A,respectively.

After forming the electrodes 207, a resin film 208 is formed over theelectrodes 207 as shown in FIG. 7B. Thereafter, laser irradiation isperformed as shown in FIG. 7C. An opening 209 is formed in theseparation layer 201, the first insulating film 202, the secondinsulating film 205, and the resin film 208, as shown in FIG. 7D. Byproviding the opening 209, the separation layer 201 is partly removed sothat a stacked body 211 including a layer 210 including a resistor, inwhich the first insulating film 202, the resistive element 204, thesecond insulating film 205, and the electrodes 207 are stacked, and theresin film 208 can be easily separated from the substrate 200. Thisseparation is performed at a boundary between an interior portion of theseparation layer 201 or the separation layer 201 and the firstinsulating film 202.

Further, any type of a laser can be used as well as Embodiment Mode 1.Laser irradiation conditions such as a frequency, power density, energydensity, and a beam profile are arbitrarily controlled in considerationof thicknesses, materials and the like of the layer 210 including theresistor and the resin film 208.

In order to separate the stacked body 211 including the layer 210including the resistor and the resin film 208 from the substrate 200, afirst film 212 is attached to a surface of the resin film 208 as shownin FIG. 8A and the first film 212 is pulled in a direction of an arrowas shown in FIG. 8B, and thus the stacked body 211 including the layer210 including the resistor and the resin film 208 is separated from thesubstrate 200. In this case, the substrate 200 and the stacked body 211are separated from each other at a boundary between the interior portionof the separation layer 201 or the separation layer 201 and the firstinsulating film 202. In the stacked body 211 separated from thesubstrate 200, the first insulating film 202 becomes an outermostsurface. The resin film 208 secures strength when separating thesubstrate 200 and the stacked body 211 from each other by pulling thefirst film 212. The stacked body 211 can be prevented from breaking inthis step by the resin film 208.

The first film 212 has a structure in which an adhesive layer isprovided on a base film made from a resin material. For example, a hotmelt film, a UV (ultraviolet) separating film, a heat separating film,and the like can be given. As a material used for the base film,polyester, PET (polyethylene terephthalate), PEN (polyethylenenaphthalate), and the like can be given.

A hot melt film has a structure in which over a base film, an adhesivelayer made from a resin having a softening point, which is lower thanthat of the base film, is formed. A polyethylene resin, polyester, EVA(ethylene vinyl acetate), and the like can be given as a material usedfor the adhesive layer. A UV (ultraviolet) separating film has astructure in which an adhesive layer made from a resin material whoseadhesion is weakened by being irradiated with a UV (ultraviolet) ray, isformed over a base film. Further, a heat separating film has a structurein which an adhesive layer made from a resin material whose adhesion isweakened by heating is formed over a base film.

When a UV (ultraviolet) separating film is used as the first film 212,the first film 212 can be separated by being irradiated with UV(ultraviolet) ray after the separating step.

Further, when a heat separating film is used as the first film 212, thefirst film 212 can be separated by heating after the separating step.

Then, as shown in FIG. 8C, conductive films 213 each having a thicknessof 1 μm to several tens of μm, and preferably, 10 μm to 20 μm, areformed over a surface of the first insulating film 202 (a back surfaceof the thin film circuit), i.e., the surface of the first insulatingfilm 202 over which the layer 210 including the circuit having theresistor is not formed, such that the conductive films are overlappedwith the electrodes 207. The conductive films 213 may be formed using aconductive material such as an Au paste, an Ag paste, a Cu paste, an Nipaste, or an Al paste, solder, or the like by screen printing, forexample. When each thickness of the conductive films 213 is 0.1 μm orless, the conductive films cannot be electrically connected to theelectrodes 207 in a subsequent step because of their excessive thinthicknesses.

Then, as shown in FIG. 8D, the conductive films 213 are irradiated withlaser beams. In this case, output of a laser is adjusted such that theconductive films 213 are moved to reach the electrodes 207 and the movedconductive films 213 are stopped at the electrodes 207. In this case,laser irradiation is performed by using an Nd:YVO₄ pulse laser with alaser wavelength of 266 nm under conditions of an oscillation frequencyof 15 kHz and an average output of 3 W. These conditions are typicalconditions and the present invention is not limited thereto. Theconductive films 213 and the electrodes 207 are electrically connectedto one another by the laser irradiation, and hence, a state shown inFIG. 9 is obtained. In FIG. 9, reference numerals 214 and 215 indicatethe conductive films being electrically connected to the electrodes 207.

As shown in FIG. 9, holes are formed in the first insulating film 202and the second insulating film 205 at positions irradiated with laserbeams, and a material of the conductive films 213 is moved inside theelectrodes 207 along side walls of the holes; therefore, the conductivefilms 213 are electrically connected to the electrodes.

Note that an example where the output of the laser is adjusted such thatthe conductive films 213 are moved to reach the electrodes 207 andstopped at the electrodes 207, is shown here. Alternatively, the outputof the laser may be adjusted such that holes passing through the resinfilm 208 and the first film 212 are formed.

Embodiment Mode 3

In this embodiment mode, a case of forming a circuit having an inductoras a thin film circuit will be described. Although a case of forming acircuit having one kind of an element is shown in this embodiment mode,a case where a circuit has plural kinds of elements selected from a thinfilm transistor, a resistor, an inductor, and a capacitor can also beimplemented.

A manufacturing process of an integrated circuit device having aninductor will be described with reference to cross sectional viewsfocusing on a portion where the inductor is formed.

First, as shown in FIG. 11A, a separation layer 301 is formed over asubstrate 300, and a first insulating film 302 is formed over theseparation layer 301. The substrate 300 and the separation layer 301 maybe formed using the same materials and the same formation methodsdescribed in Embodiment Mode 1.

Next, as shown in FIG. 11B, a first conductive film 303 having a coiledshape is formed over the first insulating film 302. In FIG. 11B, anupper portion is a cross sectional view whereas a lower portion is a topview. In the top view of FIG. 11B, regions 304 and 305 are regions forcontacting to electrodes, which will be formed later.

After forming the first conductive film 303, a resin film 306 is formedover the first conductive film 303 as shown in FIG. 11C. Then, the resinfilm 306 is irradiated with a laser beam as shown in FIG. 12A. Anopening 307 is formed in the separation layer 301, the first insulatingfilm 302, and the resin film 306 by laser irradiation, as shown in FIG.12B. By forming the opening 307, the separation layer 301 is partlyremoved so that a stacked body 309 including a layer 308 including acircuit having the inductor, in which the first insulating film 302 andthe first conductive film 303 are stacked, and the resin film 306 can beeasily separated from the substrate 300. This separation is performed ata boundary between an interior portion of the separation layer 301 orthe separation layer 301 and the first insulating film 302.

Further, any type of a laser can be used as well as Embodiment Mode 1.Laser irradiation conditions such as a frequency, power density, energydensity, and a beam profile are arbitrarily controlled in considerationof thicknesses, materials and the like of the layer 308 including thecircuit having the inductor and the resin film 306.

In order to separate the stacked body 309 including the layer 308including the circuit having the inductor and the resin film 306 fromthe substrate 300, a first film 310 is attached to a surface of theresin film 306 as shown in FIG. 12C and the first film 310 is pulled ina direction of an arrow as shown in FIG. 12D; therefore, the stackedbody 309 including the layer 308 including the circuit having theinductor and the resin film 306 is separated from the substrate 300. Astate of the stacked body 309 and the first film 310 separated from thesubstrate 300 is shown in FIG. 13A. When the stacked body 309 isseparated from the substrate 300, the substrate 300 and the stacked body309 are separated from each other at a boundary between the interiorportion of the separation layer 301 or the separation layer 301 and thefirst insulating film 302. In the stacked body 309 separated from thesubstrate 300, the first insulating film 302 becomes an outermostsurface. The resin film 306 secures strength when separating thesubstrate 300 and the stacked body 309 from each other by pulling thefirst film 310. The stacked body 309 can be prevented from breaking inthis step by the resin film 306.

The first film 310 has a structure in which an adhesive layer isprovided on a base film made from a resin material. For example, a hotmelt film, a UV (ultraviolet) separating film, a heat separating film,and the like can be given. As a material used for the base film,polyester, PET (polyethylene terephthalate), PEN (polyethylenenaphthalate), and the like can be given.

A hot melt film has a structure in which over a base film, an adhesivelayer made from a resin having a softening point, which is lower thanthat of the base film, is formed. A polyethylene resin, polyester, EVA(ethylene vinyl acetate), and the like can be given as a material forthe adhesive layer. A UV (ultraviolet) separating film has a structurein which an adhesive layer made from a resin material, whose adhesion isweakened by being irradiated with a UV (ultraviolet) ray, is formed overa base film. A heat separating film has a structure in which an adhesivelayer made from a resin material whose adhesion is weakened by heatingis formed over a base film.

When a UV (ultraviolet) separating film is used as the first film 310,the first film 310 can be separated by being irradiated with UV(ultraviolet) ray after the separating step.

Further, when a heat separating film is used as the first film 310, thefirst film 310 can be separated by heating after the separating step.

Then, as shown in FIG. 13B, second conductive films 311 each having athickness of 1 μm to several tens of μm, and preferably, 10 μm to 20 μm,are formed over a surface of the first insulating film 302 (a backsurface of a thin film circuit), i.e., the surface of the firstinsulating film 302 over which the layer 308 including the circuithaving the inductor is not formed, such that the second conductive filmsare overlapped with the regions 304 and 305 of the first conductive film303, respectively. The second conductive films 311 may be formed using aconductive material such as an Au paste, an Ag paste, a Cu paste, an Nipaste, or an Al paste, solder, or the like by screen printing, forexample. When the thickness of each of the second conductive films 311is 0.1 μm or less, the second conductive films cannot be electricallyconnected to the first conductive film 303 in a subsequent step becauseof their excessive thin thickness.

FIG. 13B is a cross sectional view along a line A-A′ of the top surfaceshown in FIG. 11B. Only a single second conductive film 311, which isformed at a position overlapping with the region 305 of the firstconductive film 303 shown in FIG. 11B, is shown in FIG. 13B; however,other second conductive film is also formed at a position overlappingwith the region 304 of the first conductive film 303.

Then, as shown in FIG. 13C, the second conductive film 311 is irradiatedwith laser beams. In this case, output of a laser is adjusted such thatthe second conductive film 311 is moved to reach the first conductivefilm 303 and the moved second conductive film 311 is stopped at thefirst conductive film 303. Laser irradiation is performed by using anNd:YVO₄ pulse laser with a laser wavelength of 266 nm under conditionsof an oscillation frequency of 15 kHz and an average output of 3 W.These conditions are typical conditions and the present invention is notlimited thereto. The second conductive film 311 and the first conductivefilm 303 are electrically connected to each other by the laserirradiation, and hence, a state shown in FIG. 13D is obtained. In FIG.13D, reference numeral 312 indicates the second conductive film beingelectrically connected to the first conductive film 303.

As shown in FIG. 13D, a hole is formed in the first insulating film 302at a position irradiated with the laser beam, and a material of thesecond conductive film 311 is moved inside the first conductive film 303along a side wall of the hole; therefore, the second conductive film 311is electrically connected to the first conductive film.

Note that an example where the output of the laser is adjusted such thatthe second conductive film 311 is moved to reach the first conductivefilm 303 and stopped at the first conductive film 303, is shown here.Alternatively, the output of the laser may be adjusted such that a holepassing through the resin film 306 and the first film 310 is formed.

Embodiment Mode 4

A method for forming an integrated circuit device having a capacitor asa thin film circuit will be described in this embodiment mode. Althougha case of forming a circuit having one kind of an element will bedescribed in this embodiment mode, a case of a circuit having pluralkinds of elements selected from a thin film transistor, a resistor, aninductor, and a capacitor, can also be implemented.

First, as shown in FIG. 14A, a separation layer 401 is formed over asubstrate 400, and a first insulating film 402 is formed over theseparation layer 401. The substrate 400 and the separation layer 401 maybe formed using the same materials and the same formation methods asdescribed in Embodiment Mode 1.

Next, as shown in FIG. 14B, a first electrode 403 of a capacitor isformed over the first insulating film 402. A metal film or the like maybe formed as the first electrode 403 of the capacitor, for example.Next, a second insulating film 404 is formed as shown in FIG. 14C. Thesecond insulating film 404 may be formed using a dielectric substancesuch as TiO₂, Al₂O₃, BaTiO₃, or SiO₂.

Then, as shown in FIG. 14D, a second electrode 405 of the capacitor isformed. The second electrode 405 of the capacitor may be formed using ametal film or the like as well as the first electrode of the capacitor.Thus, the capacitor including the first electrode, the insulating film,and the second electrode is formed.

Subsequently, a resin film 406 is formed over the capacitor manufacturedabove as shown in FIG. 15A. The resin film 406 is provided for securingstrength of the thin film circuit. After forming the resin film 406,laser irradiation is performed as shown in FIG. 15B. By the laserirradiation, an opening 407 is formed in the separation layer 401, thefirst insulating film 402, the second insulating film 404, and the resinfilm 406 as shown in FIG. 15C. By forming the opening 407, theseparation layer 401 is partly removed so that a stacked body 409including a layer 408 including a circuit having the capacitor, in whichthe first insulating film 402, the first electrode 403, the secondinsulating film 404, and the second electrode 405 are stacked, and theresin film 406 can be easily separated from the substrate 400. Thisseparation is performed at a boundary between an interior portion of theseparation layer 401 or the separation layer 401 and the firstinsulating film 402.

Further, any type of a laser can be used as well as Embodiment Mode 1.Laser irradiation conditions such as a frequency, power density, energydensity, and a beam profile are arbitrarily controlled in considerationof thicknesses, materials and the like of the layer 408 including thecircuit having the capacitor and the resin film 406.

In order to separate the stacked body 409 including the layer 408including the circuit having the capacitor and the resin film 406 fromthe substrate 400, a first film 410 is attached to a surface of theresin film 406 as shown in FIG. 15D and the first film 410 is pulled ina direction of an arrow as shown in FIG. 16A; therefore, the stackedbody 409 including the layer 408 including the circuit having thecapacitor and the resin film 406 is separated from the substrate 400. Astate of the stacked body 409 and the first film 410 separated from thesubstrate 400 is shown in FIG. 16B. When the stacked body 409 isseparated from the substrate 400, the substrate 400 and the stacked body409 are separated from each other at a boundary between the interiorportion of the separation layer 401 or the separation layer 401 and thefirst insulating film 402. In the stacked body 409 separated from thesubstrate 400, the first insulating film 402 becomes an outermostsurface. The resin film 406 secures strength when separating thesubstrate 400 and the stacked body 409 from each other by pulling thefirst film 410. The stacked body 409 can be prevented from breaking inthis step by the resin film 406.

The first film 410 has a structure in which an adhesive layer isprovided over a base film made from a resin material. For example, a hotmelt film, a UV (ultraviolet) separating film, a heat separating film,and the like can be given. As a material used for the base film,polyester, PET (polyethylene terephthalate), PEN (polyethylenenaphthalate), and the like can be given.

A hot melt film has a structure in which over a base film, an adhesivelayer made from a resin having a softening point, which is lower thanthat of the base film, is formed. A polyethylene resin, polyester, EVA(ethylene vinyl acetate), and the like can be given as a material usedfor the adhesive layer. A UV (ultraviolet) separating film has astructure in which an adhesive layer made from a resin material whoseadhesion is weakened by being irradiated with a UV (ultraviolet) ray, isformed over a base film. A heat separating film has a structure in whichan adhesive layer made from a resin material whose adhesion is weakenedby heating is formed over a base film.

When a UV (ultraviolet) separating film is used as the first film 410,the first film 410 can be separated by being irradiated with UV(ultraviolet) ray after the separating step.

Further, when a heat separating film is used as the first film 410, thefirst film 410 can be separated by heating after the separating step.

Then, as shown in FIG. 16C, conductive films 411 and 412 each having athickness of 1 μm to several tens of μm, and preferably, 10 μm to 20 μm,are formed over a surface of the first insulating film 402 (a backsurface of a thin film circuit), i.e., the surface of the firstinsulating film 402 over which the layer 408 including the circuithaving the capacitor is not formed, such that the conductive films areoverlapped with part of the first electrode 403 and part of the secondelectrode 405, respectively. The conductive films 411 and 412 may beformed using a conductive material such as an Au paste, an Ag paste, aCu paste, an Ni paste, or an Al paste, solder, or the like by screenprinting, for example. When a thickness of each of the conductive films411 and 412 is 0.1 μm or less, the conductive films cannot beelectrically connected to the first electrode 403 and the secondelectrode 405 in a subsequent step because of their excessive thinthicknesses.

Then, as shown in FIG. 16D, the conductive films 411 and 412 areirradiated with laser beams. Output of a laser is adjusted such that theconductive film 411 is moved to reach the first electrode 403, and themoved conductive film 411 is stopped at the first electrode 403.Further, output of the laser is adjusted such that the conductive film412 is moved to reach the second electrode 405, and the moved conductivefilm 412 is stopped at the second electrode 405. In this case, laserirradiation is performed by using an Nd:YVO₄ pulse laser with a laserwavelength of 266 nm under conditions of an oscillation frequency of 15kHz and an average output of 3 W. These conditions are typicalconditions and the present invention is not limited thereto. Theconductive film 411 and the first electrode 403 are electricallyconnected to each other and the conductive film 412 and the secondelectrode 405 are electrically connected to each other by the laserirradiations, and hence, a state shown in FIG. 17 is obtained. In FIG.17, reference numeral 413 indicates the conductive film beingelectrically connected to the first electrode 403 and reference numeral414 indicates the conductive film being electrically connected to thesecond electrode 405.

As shown in FIG. 17, a hole is formed in the first insulating film 402at a position irradiated with the laser beam for forming the conductivefilm 413 being electrically connected to the first electrode 403, and amaterial of the conductive film 413 is moved to the first electrode 403along a side wall of the hole; therefore, the conductive film 413 iselectrically connected to the first electrode. Further, a hole is formedin the first insulating film 402 and the second insulating film 404 at aposition irradiated with the laser beam for forming the conductive film414 being electrically connected to the second electrode 405, and amaterial of the conductive film 414 is moved to the second electrode 405along a side wall of the hole; therefore, the conductive film 414 iselectrically connected to the second electrode.

Note that an example where the output of the laser is adjusted such thatthe conductive film 411 is moved to reach the first electrode 403 andstopped at the first electrode 403 when forming the conductive film 413being electrically connected to the first electrode 403 whereas theoutput of the laser is adjusted such that the conductive film 414 ismoved to reach the second electrode 405 and stopped at the secondelectrode 405 when forming the conductive film 414 being electricallyconnected to the second electrode 405, is shown here. Alternatively, theoutput of the laser in forming the conductive film 413 beingelectrically connected to the first electrode and output of the laser informing the conductive film 414 being electrically connected to thesecond electrode may be adjusted such that holes passing through theresin film 406 and the first film 410 are formed.

Embodiment Mode 5

A case in which a flexible integrated circuit device is formed byreducing a thickness of a substrate by grinding, polishing or the likewill be described in this embodiment mode, though a case of forming aflexible integrated circuit device by separating a stacked bodyincluding a layer including a circuit having a thin film transistor froma substrate is described in Embodiment Mode 1. Although a case offorming a thin film transistor as a thin film circuit will be describedin this embodiment mode, a case of a thin film circuit having one orplural kinds of elements selected from a thin film transistor, aresistor, an inductor, and a capacitor can also be implemented.

First, as shown in FIG. 18A, a first insulating film 501 is formed overa first substrate 500. This first insulating film serves as a base film.The first insulating film 501 is formed using silicon oxide, siliconnitride, silicon oxide containing nitrogen, silicon nitride containingoxygen, or the like by plasma CVD, sputtering, or the like.

As the first substrate 500, a quartz substrate, a semiconductorsubstrate, a glass substrate, a metal substrate, or the like may beused.

As shown in FIG. 18B, a layer 504 including circuits 503 having thinfilm transistors is formed over the first insulating film 501 by a knownmethod. As the layer 504 including the circuits 503 having the thin filmtransistors, for example, a plurality of thin film transistors, a secondinsulating film 510 covering the plurality of thin film transistors,source or drain wirings 511 being in contact with the second insulatingfilm 510 and connected to source or drain regions of the plurality ofthin film transistors, are formed. Each of the plurality of thin filmtransistors includes an island-like semiconductor film 507, a gateinsulating film 508, a gate electrode 509 provided with a sidewall, andthe like. In FIG. 18B, a circuit including an N-channel thin filmtransistor 505 and a P-channel thin film transistor 506 is shown as anexample of each of the circuits 503 having the thin film transistors;however, the present invention is not limited thereto. Further, anexample where a top-gate thin film transistor having an LDD region (alow concentration impurity region) along with a gate electrode providedwith a sidewall is formed as each of the N-channel thin film transistors505 whereas a top-gate thin film transistor having a gate electrodeprovided with a sidewall is formed as each of the P-channel thin filmtransistors 506, is shown in FIG. 18B; however, the present invention isnot limited thereto. A known structure of a thin film transistor such asa thin film transistor having no LDD region (no low concentrationimpurity region) or a bottom-gate thin film transistor is applicable.

Note that the circuits 503 having the thin film transistors can beformed using the manufacturing method described in Embodiment Mode 1.

Next, as shown in FIG. 18C, a third insulating film 512 is formed overthe layer 504 including the circuits 503 having the thin filmtransistors, and electrodes 513 being electrically connected to wiringsof the circuits 503 having the thin film transistors are formed over thethird insulating film 512.

The third insulating film 512 is formed by a single layer or a stackedlayer made from an inorganic material such as silicon oxide, siliconnitride, silicon oxynitride, or silicon nitride oxide; an organicmaterial such as polyimide, polyamide, benzocyclobutene, acrylic, orepoxy; siloxane; or the like by a known method.

The electrodes 513 are formed to be electrically connected to the sourceor drain wirings of the thin film transistors in FIG. 18C; however, thepresent invention is not limited to this case. An electrode may beformed at a position to be electrically connected to an external circuitin a thin film circuit.

Next, as shown in FIG. 19A, a fourth insulating film 514 is formed overthe electrodes 513. The fourth insulating film 514 is formed by a singlelayer or a stacked layer using an inorganic material such as siliconoxide, silicon nitride, silicon oxynitride, or silicon nitride oxide; anorganic material such as polyimide, polyamide, benzocyclobutene,acrylic, or epoxy; siloxane; or the like by a known method.

Then, as shown in FIG. 19B, a second substrate 515 is attached to asurface of the fourth insulating film 514 by using an adhesive material.As the second substrate 515, a quartz substrate, a semiconductorsubstrate, a glass substrate, a metal substrate, a resin substrate, orthe like can be used. An adhesive material whose adhesion is weakened byheating is preferably used. In addition, a film having a structure wherean adhesive layer is provided on a base film such as a hot melt film, aUV (ultraviolet) separating film, or a heat separating film may be usedas the second substrate.

In a case where the second substrate 515 is not attached to the surfaceof the fourth insulating film 514, in a step of reducing a thickness ofthe first substrate 500, which will be performed later, as reducing thethickness of the first substrate 500, a stacked body including the layer504 including the circuits having the thin film transistor, the thirdinsulating film 512, the electrodes 513, and the fourth insulating film514, may be curved. However, attaching the second substrate 515 to thesurface of the fourth insulating film 514 makes it possible to preventthe stacked body including the layer 504 including the circuits havingthe thin film transistors, the third insulating film 512, the electrodes513, and the fourth insulating film 514, from being curved in the stepof reducing the thickness of the first substrate 500, which will beperformed later.

After attaching the second substrate to the surface of the fourthinsulating film 514, treatment for reducing the thickness of the firstsubstrate 500 is performed. By this treatment, the thickness of thefirst substrate 500 is reduced to be 100 μm or less, and preferably, 20to 50 μm. The thickness of the first substrate 500 is reduced by using agrinding means or polishing means 516 here as shown in FIG. 19C. In thiscase, the thickness of the first substrate 500 may be reduced bygrinding the substrate only using the grinding means. Alternatively, thethickness of the first substrate 500 may be reduced by polishing thesubstrate only using the polishing means. Preferably, after the firstsubstrate is subjected to grinding by the grinding means, the substrateis polished by the polishing means.

As a means for reducing the thickness of the first substrate 500, thegrinding means or polishing means is employed here; however, the presentinvention is not limited thereto. As a means for reducing the thicknessof the first substrate 500, wet etching may be used. In this case, whena film being resistant to an etching solution, by which the firstsubstrate 500 is etched, is formed between the first substrate 500 andthe first insulating film 501, the first insulating film 501 can beprevented from being etched.

After performing the treatment for reducing the thickness of the firstsubstrate 500, a state of the first substrate 500 having a reducedthickness is shown in FIG. 20A. FIG. 20A shows a state where part of thefirst substrate 500 remains; however, the first substrate 500 may beentirely removed or part of the first substrate 500 remains on thesurface of the first insulating film 501.

Then, as shown in FIG. 20B, conductive films 517 each having a thicknessof 1 μm to several tens of μm, and preferably, 10 μm to 20 μm, areformed over a surface of the first substrate 500 over which the firstinsulating film 501 is not provided, i.e., a back surface of a thin filmcircuit, such that the conductive films are overlapped with theelectrodes 513. The conductive films 517 may be formed using aconductive material such as an Au paste, an Ag paste, a Cu paste, an Nipaste, or an Al paste, solder, or the like by screen printing, forexample. When a thickness of each of the conductive films 517 is 0.1 μmor less, the conductive films cannot be electrically connected to theelectrodes 513 in a subsequent step because of their excessive thinthicknesses.

Then, as shown in FIG. 20C, the conductive films 517 are irradiated withlaser beams. In this case, output of a laser is adjusted such that theconductive films 517 are moved to reach the electrodes 513 and the movedconductive films 517 are stopped at the electrodes 513. Laserirradiation is performed by using an Nd:YVO₄ pulse laser with a laserwavelength of 266 nm under conditions of an oscillation frequency of 15kHz and an average output of 3 W. These conditions are typicalconditions and the present invention is not limited thereto. Theconductive films 517 and the electrodes 513 are electrically connectedto one another by the laser irradiation, and hence, a state shown inFIG. 21A is obtained. In FIG. 21A, reference numeral 518 indicates oneof the conductive films being electrically connected to the electrode513.

As shown in FIG. 21A, holes are formed in the first substrate 500, thelayer 504 including the circuits 503 having the thin film transistors,and the third insulating film 512 at positions irradiated with laserbeams, and a material of the conductive films 517 is moved to theelectrodes 513 along side walls of the holes; therefore, the conductivefilms 517 are electrically connected to the electrodes.

Note that an example where the output of the laser is adjusted such thatthe conductive films 517 are moved to reach the electrodes 513 andstopped at the electrodes 513, is shown here. Alternatively, the outputof the laser may be adjusted such that holes passing through the fourthinsulating film 514 and the second substrate 515 are formed.

By irradiating each portion between the adjacent circuits 503 having thethin film transistors with laser beams as shown in FIG. 21B, thecircuits 503 having the thin film transistors are individually dividedinto three portions 519, 520, and 521 each having the thin filmtransistors. The divided portions 519, 520, and 521 become integratedcircuit devices, respectively.

A case where the three circuits 503 having the thin film transistors areformed over the substrate is described in this embodiment mode; however,the number of the circuits 503 having the thin film transistors providedover the substrate is not limited thereto. It goes without saying thatthe number of the circuit 503 having the thin film transistors may beone, two, or three or more.

As described above, integrated circuit devices of the present inventionare formed. A step of forming a semiconductor device by mounting anintegrated circuit device of the present invention obtained above over asubstrate, over which an antenna is formed, will be described below.

As shown in FIG. 22A, a conductive film 523 having a function of anantenna is formed over a substrate 522. An integrated circuit device 526is attached to a surface of the substrate 522 by using a resin 524containing conductive particles 525. By attaching the integrated circuitdevice 526 and the substrate 522 using the resin 524 containing theconductive particles 525, connection portions of the conductive film 523having the function of the antenna are electrically connected toconnection conductive films provided adjacent to a back surface of theintegrated circuit device 526 through the conductive particles 525.

Then, heat treatment is performed to cure the resin 524 containing theconductive particles 525. When the second substrate 515 is attached tothe fourth insulating film 514 by using an adhesive material whoseadhesion is weakened by heating, or when a heat separating film is usedas the second substrate 515, the second substrate 515 can be separatedfrom the fourth insulating film 514 by this heat treatment. A stateafter separating the second substrate 515 from the fourth insulatingfilm 514 is shown in FIG. 22B.

As described above, the integrated circuit device of the presentinvention can be mounted over the substrate over which the antenna isformed. Note that a case where the conductive film having the functionof the antenna and the integrated circuit device are electricallyconnected to each other by using the resin containing the conductiveparticles is described here. Alternatively, as a material forelectrically connecting the conductive film having the function of theantenna to the integrated circuit device, a known material such assolder may be used, in addition to the resin containing the conductiveparticles.

In a case of using solder as a material for electrically connecting theconductive film having the function of the antenna to the integratedcircuit device, heat treatment is also performed to melt the solder.Therefore, in a case where the second substrate 515 is attached to thefourth insulating film 514 by using an adhesive material whose adhesionis weakened by heating, or when a heat separating film is used as thesecond substrate 515, the second substrate 515 can be separated from thefourth insulating film 514 by this heat treatment.

After mounting the integrated circuit device of the present inventionover the substrate over which the antenna is formed, sealing ispreferably performed. At least one surface of the substrate 522, overwhich the conductive film 523 having the function of the antenna isformed, may be sealed. A case where only one surface of the substrate522, over which the conductive film 523 having the function of theantenna is formed, is sealed will be shown in FIG. 23A. When sealing isperformed, the conductive film having the function of the antenna issealed with a film 529 having a structure in which an adhesive layer isprovided over a base film. As the film 529, a hot melt film can begiven, for example. A hot melt film has a structure in which over a basefilm, an adhesive layer made from a resin having a softening point,which is lower than that of the base film, is formed. As a material usedfor the base film, polyester, PET (polyethylene terephthalate), PEN(polyethylene naphthalate), and the like can be given. A polyethyleneresin, polyester, EVA (ethylene vinyl acetate), and the like can begiven as a material used for the adhesive layer.

Further, as shown in FIG. 23B, the substrate 522 over which the antennais formed may be sealed with two films 527 and 528. As the films 527 and528 shown in FIG. 23B, films each having a structure having an adhesivelayer formed over a base film may be used.

Although a case where the second substrate 515 is separated at the timeof heat treatment and then the conductive film having the function ofthe antenna is sealed is described in FIGS. 22A and 22B and FIGS. 23Aand 23B, the conductive film having the function of the antenna can besealed while the second substrate 515 is attached to the surface of thefourth insulating film 514 without separating the second substrate 515.In this case, an adhesive agent used for attaching the second substrate515 to the fourth insulating film 514 is not particularly limited, andan adhesive material whose adhesion is weakened by heating is notnecessary to be used. Further, a film (such as a hot melt film) otherthan a heat separating film can be used as the second substrate.

Embodiment 1

In this embodiment, an example of mounting integrated circuit devices ofthe present invention over a substrate including a plurality of wiringswill be described with reference to FIGS. 26A and 26B.

In FIG. 26A, integrated circuit devices 601 to 604 of the presentinvention are attached to a surface of a substrate 600 having aplurality of wirings 605. In each of the integrated circuit devices 601to 604, square portions surrounded by dashed lines are connectionportions where thin film circuits and the wirings provided over thesubstrate 600 are connected.

An enlarged view of a cross section of a single connection portion 606,which is one of the connection portions, is shown in FIG. 26B. As shownin FIG. 26B, a wiring 607 provided over the substrate 600 and aconnection conductive film provided adjacent to a back surface of theintegrated circuit device 604 are attached to each other by a resin 609containing conductive particles 608. Since the connection conductivefilm provided adjacent to the back surface of the integrated circuitdevice is electrically connected to the circuit included in theintegrated circuit device, a wiring provided over the substrate can beelectrically connected to the circuit included in the integrated circuitdevice.

Further, the connection conductive films provided adjacent to the backsurfaces of the integrated circuit devices 601 to 604 are attached tothe wirings formed over the substrate with the resin 609 containing theconductive particles 608 in the same manner as the above describedconnection portion 606.

Each of the integrated circuit devices 601 to 604 serves as one or aplurality of a central processing unit (CPU), a memory, a networkprocessing circuit, a disc processing circuit, an image processingcircuit, an audio processing circuit, a power supply circuit, atemperature sensor, a humidity sensor, an infrared ray sensor, and thelike.

Embodiment 2

In this embodiment, an example in which integrated circuit devices ofthe present invention are applied to driver circuit portions of adisplay device, will be described with reference to FIGS. 27A and 27B.FIG. 27B shows a diagram showing a cross section along a line A-B ofFIG. 27A. In FIG. 27A, a line A-B corresponds to the line A-B of FIG.27B.

Integrated circuit devices 624 and 625 are attached to a surface of asubstrate 620, and integrated circuit devices 628 and 629 are attachedto surfaces of connection films 626 and 627. A display portion 623 andthe integrated circuit 624 are connected to each other throughconductive films 631 provided over the substrate 620. The integratedcircuit device 624 and the integrated circuit device 628 are connectedto each other through a conductive films 634 provided over the substrate620 and a conductive film 635 provided over the connection film 627.These conductive films are connected by using a resin 154 containingconductive particles 155. The substrate 620 and a counter substrate 621are attached to each other with a seal material 630.

Although an example of a case of mounting the integrated circuit devicesof the present invention over the substrate 620 and the connection films626 and 627 respectively, is shown in this embodiment, the presentinvention is not limited thereto. Integrated circuit devices of thepresent invention may be mounted only over the substrate 620 as drivercircuits, or only over the connection films.

Since an integrated circuit device of the present invention hasflexibility, it is suitable to be formed over a connection film. Whenthe integrated circuit device of the present invention is attached to acurved connection film, the integrated circuit device of the presentinvention can also be curved.

Further, a known substrate material such as a glass substrate, asemiconductor substrate, a quartz substrate, or a resin substrate can beused as the substrate 620. In particular, when using a flexiblesubstrate, since an integrated circuit device of the present inventionhas also flexibility, the integrated circuit device can be curved alongwith the substrate. As the flexible substrate, a resin substrate; aglass substrate or a semiconductor substrate whose thickness is reducedby grinding, polishing, or the like; and the like can be given.

Embodiment 3

In this embodiment, an IC card including an integrated circuit device ofthe present invention will be described with reference to FIGS. 28A to28C.

As shown in FIG. 28A, a conductive film 642 having a function of anantenna is formed over a card-type substrate 640. An integrated circuitdevice 641 of the present invention is attached to a surface of thecard-type substrate 640. The integrated circuit device 641 and theconductive film 642 having the function of the antenna are electricallyconnected to each other. An enlarged view of a cross section at aconnection portion 643 between the integrated circuit device 641 and theconductive film 642 having the function of the antenna is shown in FIG.28B.

As shown in FIG. 28B, the conductive film 642 having the function of theantenna provided over the card-type substrate 640 and a connectionconductive film provided adjacent to a back surface of the integratedcircuit device 641 are attached to each other by a resin 645 containingconductive particles 644. The connection conductive film providedadjacent to the back surface of the integrated circuit device iselectrically connected to a circuit included in the integrated circuitdevice, and therefore, the conductive film 642 having the function ofthe antenna provided over the card-type substrate 640 and the circuitincluded in the integrated circuit device 641 are electrically connectedto each other.

As the card-type substrate 640, a flexible substrate (for example, aplastic substrate) is used. Moreover, since the integrated circuitdevice of the present invention has flexibility, when it is mounted overa flexible substrate, the integrated circuit device can be curvedtogether with the card-type substrate 640 as shown in FIG. 28C.

Embodiment 4

An example of an IC card having integrated circuit devices of thepresent invention, which is different from that of Embodiment 3, will bedescribed with reference to FIGS. 29A to 29D.

As shown in FIG. 29A, a conductive film 661 having a function of anantenna is formed over a card-type substrate 660. Integrated circuitdevices 662 to 665 of the present invention are attached to a surface ofthe card-type substrate 660. The integrated circuit device 664 and theconductive film 661 having the function of the antenna are electricallyconnected to each other. An enlarged view of a cross section at aconnection portion 666 between the integrated circuit device 664 and theconductive film 661 having the function of the antenna is shown in FIG.29B.

As shown in FIG. 29B, the conductive film 661 having the function of theantenna provided over the card-type substrate 660 and a connectionconductive film provided adjacent to a back surface of the integratedcircuit device 664 are attached to each other with a resin 668containing conductive particles 667. The connection conductive filmprovided adjacent to the back surface of the integrated circuit device664 is electrically connected to a circuit included in the integratedcircuit device 664, and therefore, the conductive film 661 having thefunction of the antenna provided over the card-type substrate 660 andthe circuit included in the integrated circuit device 664 can beelectrically connected to each other.

Each of the integrated circuit devices 662 to 665 serves as one or aplurality of a central processing unit (CPU), a memory, a networkprocessing circuit, a disc processing circuit, an image processingcircuit, an audio processing circuit, a power supply circuit, atemperature sensor, a humidity sensor, an infrared ray sensor, and thelike.

The IC card of this embodiment has the integrated circuit device 664including the structure described above and the integrated circuitdevices 662, 663, and 665. Therefore, a high-performance IC card capableof performing complicated processing such as encryption processing canbe provided.

Although how to electrically connect the integrated circuit devices 662to 665 is not particularly described in FIG. 29A, the adjacentintegrated circuit devices are electrically connected to one another.

The conductive film 661 having the function of the antenna is providedaround the integrated circuit devices 662 to 665 in the structure shownin FIG. 29A; however, the present invention is not limited to this mode.As shown in FIG. 29C and FIG. 29D, the integrated circuit devices 662 to665 may be provided to overlap with the conductive film 661 having thefunction of the antenna. Providing the integrated circuit devices 662 to665 to overlap with the conductive film 661 having the function of theantenna makes it possible to reduce an area of the card-type substrate660 as compared to the case of FIG. 29A, thereby providing a small,thin, and lightweight semiconductor device. For example, in a case wherea temperature sensor is applied to any one of the integrated circuitdevices 662 to 665 of a miniaturized wireless chip and the wireless chipis attached to human skin (preferably, skin of one's forehead),measurement of body temperature can be carried out.

Embodiment 5

A semiconductor device of the present invention having an integratedcircuit device and an antenna is applicable to various fields. Specificapplication examples will be described below. Semiconductor devices 810of the present invention can be utilized to be provided over articlessuch as paper notes; coins; securities; bearer stock certificates;certificates (e.g., a driver's license, a resident card and the like,see FIG. 30A); packing containers (e.g., a wrapping paper, a plasticbottle and the like, see FIG. 30B); recording mediums (e.g., DVDsoftware, a videotape and the like, see FIG. 30C); vehicles (e.g., abicycle and the like, see FIG. 30D); personal belongings (e.g., a bag,eyeglasses and the like, see FIG. 30E); food items; clothes; livingware;and electronic appliances. The electronic appliances indicate a liquidcrystal display device, an EL display device, a television device (also,simply referred to as a television or a television receiver), a portablephone, and the like.

A single semiconductor device 810 of the present invention including anintegrated circuit device and an antenna is fixed to an article by beingattached to a surface of the article or embedded in the article. Forexample, the semiconductor device 810 is embedded in a paper of a book,or embedded in an organic resin of a package that is formed using theorganic resin. Since the semiconductor device 810 of the presentinvention is small, thin, and lightweight, after fixing it to anarticle, design of the article is not impaired by the semiconductordevice. By providing the semiconductor devices of the present inventionto bills, coins, portfolios, bearer stock certificates, certificates,and the like, identification functions can be provided to these things.By utilizing the identification functions, forgery of these things canbe prevented. In addition, by providing the semiconductor devices towrapping containers, recording mediums, personal belongings, food items,clothes, livingware, electronic appliances and the like, a system suchas an inspection system can be improved efficiently.

Next, an example of a system utilizing a semiconductor device of thepresent invention will be described. A reader/writer 895 is provided ona side surface of a portable terminal including a display portion 894,and a semiconductor device 896 of the present invention including anintegrated circuit device and an antenna is provided on a side surfaceof an article 897 (see FIG. 31A). Further, information relating to thearticle 897, such as a raw material, a place of origin of the article,and a test result per production process, is stored in the semiconductordevice 896 including the integrated circuit device of the presentinvention and the antenna in advance. When information stored in thesemiconductor device 896 of the present invention including theintegrated circuit device and the antenna is displayed on the displayportion 894 with a time the semiconductor device 896 of the presentinvention including the integrated circuit device and the antenna isheld up against the reader/writer 895, a convenient system can beprovided. As other example, the reader/writer 895 is provided on theside of a belt conveyor (see FIG. 31B). This can provide a system bywhich the article 897 can be inspected very easily. As set forth above,by utilizing a semiconductor device of the present invention to amanagement system or a distribution system of articles, performance ofthe system can be improved, making it possible to improve convenience.

The present application is based on Japanese Patent Application serialNo. 2005-161413 filed on Jun. 1, 2005 in Japanese Patent Office, theentire contents of which are hereby incorporated by reference.

1. A device comprising: a first conductive film over a substrate; asecond conductive film over and electrically connected to the firstconductive film; a transistor including a gate insulating film, aninterlayer insulating film, a source electrode and a drain electrodeover the substrate; and an electrode connected to one of the sourceelectrode and the drain electrode and electrically connected to thesecond conductive film over the transistor, wherein at least a part ofthe second conductive film is provided in a contact hole formed in thegate insulating film and the interlayer insulating film, and wherein thesecond conductive film comprises copper.
 2. The device according toclaim 1, wherein the transistor is a thin film transistor.
 3. The deviceaccording to claim 1, wherein the first conductive film is electricallyconnected to the second conductive film through conductive particles ina resin.
 4. An electric appliance including the device according toclaim
 1. 5. The electric appliance according to claim 4, wherein theelectric appliance is one of a liquid crystal display device, an ELdisplay device, a television device, and a portable phone.
 6. A devicecomprising: a first conductive film over a substrate; a secondconductive film over and electrically connected to the first conductivefilm; a transistor including a gate insulating film, an interlayerinsulating film, a source electrode and a drain electrode over thesubstrate; and an electrode connected to one of the source electrode andthe drain electrode and electrically connected to the first conductivefilm through the second conductive film over the transistor, wherein atleast a part of the second conductive film is provided in a contact holeformed in the gate insulating film and the interlayer insulating film,and wherein the second conductive film comprises copper.
 7. The deviceaccording to claim 6, wherein the transistor is a thin film transistor.8. The device according to claim 6, wherein the first conductive film iselectrically connected to the second conductive film through conductiveparticles in a resin.
 9. An electric appliance including the deviceaccording to claim
 6. 10. The electric appliance according to claim 9,wherein the electric appliance is one of a liquid crystal displaydevice, an EL display device, a television device, and a portable phone.11. A device comprising: a first conductive film over a substrate; asecond conductive film over and electrically connected to the firstconductive film; an insulating film over a part of the second conductivefilm; a transistor including a gate insulating film, an interlayerinsulating film, a source electrode and a drain electrode over thesubstrate; and an electrode connected to one of the source electrode andthe drain electrode and electrically connected to the second conductivefilm over the transistor, wherein at least a part of the secondconductive film is provided in a contact hole formed in the gateinsulating film, the interlayer insulating film, and the insulatingfilm, and wherein the second conductive film comprises copper.
 12. Thedevice according to claim 11, wherein the transistor is a thin filmtransistor.
 13. The device according to claim 11, wherein the firstconductive film is electrically connected to the second conductive filmthrough conductive particles in a resin.
 14. An electric applianceincluding the device according to claim
 11. 15. The electric applianceaccording to claim 14, wherein the electric appliance is one of a liquidcrystal display device, an EL display device, a television device, and aportable phone.
 16. A device comprising: a first conductive film over asubstrate; a second conductive film over and electrically connected tothe first conductive film; an insulating film over a part of the secondconductive film; a transistor including a gate insulating film, aninterlayer insulating film, a source electrode and a drain electrodeover the substrate; and an electrode connected to one of the sourceelectrode and the drain electrode and electrically connected to thefirst conductive film through the second conductive film over thetransistor, wherein at least a part of the second conductive film isprovided in a contact hole formed in the gate insulating film, theinterlayer insulating film, and the insulating film, and wherein thesecond conductive film comprises copper.
 17. The device according toclaim 16, wherein the transistor is a thin film transistor.
 18. Thedevice according to claim 16, wherein the first conductive film iselectrically connected to the second conductive film through conductiveparticles in a resin.
 19. An electric appliance including the deviceaccording to claim
 16. 20. The electric appliance according to claim 19,wherein the electric appliance is one of a liquid crystal displaydevice, an EL display device, a television device, and a portable phone.